Soy protein isolate -(-)-epigallocatechin gallate conjugate: Covalent binding sites identification and IgE binding ability evaluation.

The conjugate prepared from (-)-epigallocatechin gallate (EGCG) and soy protein isolate (SPI) under alkaline and aerobic conditions was analyzed using a Nano-LC-Q-Orbitrap-MS/MS technique. The sulfhydryl and free amino groups of SPI were involved in covalent binding. Fifty-one peptides were conjugated with EGCG.

Effect of non-covalent and covalent complexation of (-)-epigallocatechin gallate with soybean protein isolate on protein structure and in vitro digestion characteristics.

The present study was aimed to investigate the effects of non-covalent and covalent interactions between soy protein isolate (SPI) and different concentrations (1, 2 and 5 mM) of (-)-epigallocatechin gallate (EGCG) regarding the structural and functional properties of the complex. The combination with EGCG caused changes in the secondary structure of SPI. The covalent complexes formed at low concentrations of EGCG tended to form a network structure.

On-line screening and identification of free radical scavenging compounds in Angelica dahurica fermented with Eurotium cristatum using an HPLC-PDA-Triple-TOF-MS/MS-ABTS system.

Eurotium cristatum, a beneficial fungus isolated from Fuzhuan tea, was used to ferment Angelica dahurica for the first time. The antioxidant capacities of the extracts before and after fermentation were compared using ABTS, DPPH and FRAP assays. The results showed that the antioxidant capacities of the extracts acquired using organic solvents were greater after fermentation.